<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .hollow {
      padding: 10px 20px;
      color: #000;
      background-color: transparent;
      border: 2px solid #fff;
      font-size: 18px;
      font-weight: bold;
      position: relative;
      overflow: hidden;
      cursor: pointer;
    }
    
    .hollow::before {
      content: '';
      position: absolute;
      top: -50%;
      left: -50%;
      bottom: -50%;
      right: -50%;
      z-index: -1;
      background-color: #fff;
      transform: scale(0);
      transition: transform .5s ease-in-out;
    }
    
    .hollow:hover::before {
      transform: scale(1.5);
    }
  </style>
</head>
<body>
  <button class="hollow">Click Me</button>
</body>
</html>